As I sat alone in the local multiplex chain cinema, watching the fellow viewers trickling in, I couldn’t help but feel sorry for the couple on a date a few rows in front of me. They’d stocked up for the next couple of hours with the standard fare: a popcorn tub bigger than their own heads, a couple of XL soft drinks, a pouch full of chocolate nibbles. They may well have been wearing Star Wars t-shirts, hoping to see lead actor John Boyega in something other than Poe Dameron’s jacket, but I didn’t quite see. The point is, they almost certainly had no idea what they were letting themselves in for. To some extent, neither did I.

As a British man in his early 30s, the real tragedy of the 1967 Detroit Riots were largely lost on me until the announcement of Kathryn Bigelow’s film. It’s a film seeking to shed light on the events that unfolded at the Algiers Motel as part of the 12th Street Riot. Whilst the motives behind making the film may have been perfectly justifiable when its production was announced in January 2016, the poignancy of its release over the backdrop of the recent events in Charlottesville could only be lost on the most unaware of cinema goers.

The film is split into three acts. The first provides a backdrop to the riots and the status of the never-ending and constantly evolving racial tensions across the USA. This act also serves to introduce some of the key players in the film: Boyega stars as diplomatic security guard Melvin Dismukes; Will Poulter portrays trigger-happy policeman Philip Kraus; Algee Smith is aspiring singer and performer Larry Reed; Hannah Murray features as young female Julie Ann.

The final act is essentially a courtroom drama that covers the fallout from the middle portion, which is a breathtaking piece of cinema that Bigelow has chosen to tell in realtime. Kraus heads up a police operation to discover what is believed to be a sniper rifle fired from the Algiers Motel, with a group of innocent black men standing accused along with two white girls. The racism is evident, driving the policemen’s actions and words to breaking point, leaving several people dead and the remainder with horrific memories of the night.

It is overwhelmingly upsetting and unsettling, made even worse by the fact it is based on accounts of real events. It seems unfathomable that anyone could watch this and not wince. It’s certainly something that has stayed fresh in my mind since I saw the film, which gives me a fraction of an idea of what it must be like for the survivors of the incident.

John Boyega’s performance is perfectly nuanced as he stands by almost helpless, doing what he can to keep the accused alive. As a security guard he is afforded a degree of respect, though it is respect that is only uniform deep. It’s not an easy role to pull off. The scene in the police interrogation room that kicks of Act 3 is almost as horrifying as what has come before, and it is in this scene that Boyega really shows his acting mettle.

Will Poulter is also worth pulling out as the extraordinarily derisible policeman Kraus. It may just be so good that he will suffer typecasting for the rest of his career. The role is written so you can do nothing but hate him, but not every actor can achieve this with such little charm. That’s deliberate and is thus a genuine triumph by Poulter.

Detroit has seemingly fallen away at the box office now, failing to recoup the production costs. In a week where The Emoji Movie continues to run having made a global profit of over $30m, I can’t help but wonder whether escapism is the order of the day for film fans at the moment. Why would we want to see a long film like this when it seems to be on the news every week anyway?